Lubricant compositions having enhanced estolide content, methods of making, and uses thereof

Abstract

Various liquid and semisolid lubricant compositions are provided, in particular lubricant compositions are provided which have been chemically modified to increase a concentration of triacylglyceride estolide content. The estolides can be produced via esterification with one or more fatty acids such as palmitoleic acid, oleic acid, linoleic acid, lauric acid, palmitic acid, stearic acid, or a combination thereof. Both liquid and semisolid lubricant compositions are provided.

What is claimed is: 
     
         1 . A lubricant composition comprising a triacylglycerol (TAG) estolide, wherein the lubricant composition has been chemically modified to increase a concentration of the TAG estolide relative to a reference concentration of the TAG estolide in the otherwise same lubricant composition except without the chemical modification. 
     
     
         2 . The lubricant composition according to  claim 1 , wherein the chemical modification comprises esterification of a triacylglycerol with one or more fatty acids to produce the TAG estolide. 
     
     
         3 . The lubricant composition according to  claim 2 , wherein the one or more fatty acids are selected from the group consisting of palmitoleic acid, oleic acid, linoleic acid, lauric acid, palmitic acid, stearic acid, and a combination thereof. 
     
     
         4 . The lubricant composition according to  claim 1 , wherein the TAG estolide is capped. 
     
     
         5 . The lubricant composition according to  claim 1 , wherein the TAG estolide is uncapped. 
     
     
         6 . The lubricant composition according to  claim 1 , wherein the triacylglycerol (TAG) estolide comprises an estolide of the triglyceride of ricinoleic acid comprising up to 3 estolide additions. 
     
     
         7 . The lubricant composition according to  claim 1 , wherein the lubricant composition is in the form of a semisolid lubricant composition comprising an emulsion of (i) a thickener and (ii) an oil. 
     
     
         8 . The lubricant composition according to  claim 7 , wherein the thickener is selected from the group consisting of calcium stearate, cellulose, sodium stearate, lithium stearate, lithium 12-hydroxystearate, and a combination thereof. 
     
     
         9 . The lubricant composition according to  claim 1 , further comprising one or more grease additives. 
     
     
         10 . The lubricant composition according to  claim 9 , wherein the one or more grease additives are selected from the group consisting of an antioxidant, an antiwear additive, a corrosion inhibitor, a detergent, a metal deactivator, a viscosity modifier, a dispersant, and a combination thereof. 
     
     
         11 . The lubricant composition according to  claim 10 , wherein the one or more grease additives comprise an antioxidant, and
 wherein the antioxidant is selected from the group consisting of (+)-α-tocopherol (TCP), propyl gallate (PG), l-ascorbic acid 6-palmitate (AP), 4,4′-methylenebis(2,6-di-tert-butylphenol) (MBP), butylated hydroxyl anisole (BHA), butylated hydroxyl toluene (BHT), propyl gallate (PG), and tert-butyl hydroquinone (TBHQ).   
     
     
         12 . The lubricant composition according to  claim 10 , wherein the one or more grease additives comprise an antiwear additive, and
 wherein the antiwear additive is selected from the group consisting of zinc dithiophosphate (ZDP), zinc dialkyl dithiophosphate (ZDDP), tricresyl phosphate (TCP), dioleoyl phosphite, bis(2-ethylhexyl) phosphate, diphenyl cresyl phosphate, triphenyl phosphorothionate, chlorinated paraffins, glycerol monooleate, and a combination thereof.   
     
     
         13 . The lubricant composition according to  claim 10 , wherein the one or more grease additives comprise a corrosion inhibitor, and
 wherein the corrosion inhibitor is selected from the group consisting of a thiadiazole, a benzotriazole, a tolutriazole, a zinc dithiophosphate, a metal phenolate, a metal sulfonate, a fatty acid, a carboxylic acid, an amine, and a combination thereof.   
     
     
         14 . The lubricant composition according to  claim 10 , wherein the one or more grease additives comprise a detergent, and
 wherein the detergent is selected from the group consisting of a polyisobutylene succinimide, a polyisobutylene amine succinamide, an aliphatic amine, a polyolefin maleic anhydride, and a combination thereof.   
     
     
         15 . The lubricant composition according to  claim 10 , wherein the one or more grease additives comprise a metal deactivator, and
 wherein the metal deactivator is selected from the group consisting of a triazole, a tolyltriazole, a thiadiazole, and a combination thereof.   
     
     
         16 . The lubricant composition according to  claim 10 , wherein the one or more grease additives comprise a viscosity modifier, and
 wherein the viscosity modifier is selected from the group consisting of an ethylene-olefin co-polymer, a maleic anhydride-styrene alternating copolymer, a polymethacrylate, a hydrogenated styrene-butadiene copolymer, a hydrogenated styrene-isoprene copolymer, an ester thereof, and a combination thereof.   
     
     
         17 . The lubricant composition according to  claim 10 , wherein the one or more grease additives comprise a dispersant, and
 wherein the dispersant is selected from the group consisting of succinimide, benzylamine, and a combination thereof.   
     
     
         18 . A method of making a lubricant composition comprising chemically modifying a base oil to increase a concentration of the TAG estolide relative to a reference concentration of the TAG estolide in the base oil without the chemical modification. 
     
     
         19 . The method according to  claim 18 , wherein the chemical modification comprises esterification of a triacylglycerol with one or more fatty acids to produce the TAG estolide. 
     
     
         20 . The method according to  claim 19 , wherein the one or more fatty acids are selected from the group consisting of palmitoleic acid, oleic acid, linoleic acid, lauric acid, palmitic acid, stearic acid, and a combination thereof.